Merocyanines and process for their preparation



Patented Sept, 20, 1949 MEROCY ANINES AND'PROCESS FOR THEIR PREPARATION Alfred W. Anish, Vestal, N. Y., assignor to General Aniline& Film Corporation, New York, N. Y., a corporation of Delaware t N Drawing; Application December 7, 1945,

SeriabNo. 633,537 "7 Claims. (01. 260-240) 1 The present invention relates to new merocyanine dyes and to methods for their production. Merocyanine dyes and their use as photographic sensitizers are already well-known. In general, the merocyanines are the condensation products of sensitizing dye intermediates possessing an active methylene group, such as is present in thiazolidones, oxazolidones, pyrimidones, pyrazolines,rhodanines, etc., all of which are characterized by having a keto-methylene nuclear structure. However, in the heretofore known merocyanine dyes the keto-methylene structure is a part of a monocyclic molecule. 1

According to my invention, I have found that dyes having strong sensitizing properties can be The dyes comprising my invention may be rep l resented by the following formulae:

II ,7N,\ ,c c"='o 1% wherein X and Z represent the atoms necessary to complete anitrogenous heterocyclic nucleus usual in the cyanine dye art, n represents a positive integer ranging from 1 to 3, and R represents an alkyl group.

More particularly, 'X, for example, represents the non-metallic atoms necessary to complete a heterocyclic nucleus containing, for instance, a member of the oxazole' series, e: g. benzoxazole; or a member of the thiazole series, e. g. benzothiazole; or a member of the thiazoline series, e. g. thiazoline; or a member of the pyridine series, e. g. pyridine; or of the quinoline series, e. g. benzoquinoline; or of the selenazole series, e. g. benzselenazole; or of the selenazoline series, e. g. selenazoline, or of; the indolenine-series, e. g. 3,3-dimethylindo1enine.

More particularly, 2 represents, for instance, the non-metallic atoms necessary to complete a heterocyclic nucleus suchmas of-the thiazoline or selenazoline series,'e. g. thiazoline or selenazoline; or of the benzthiazole series, hexahydrobenzthiazole; or of the pyrazolone series, e. g. 3- phenylpyrazolone; or of 'the'pyridineor quinoline series, e. g. pyridine or quinoline or of the thiazine series, e. g. thiazine. More particularly, B may represent methyl, ethyl, butyl, isopropyl, allyl, benzyl, n-amyl, and p-ethoxyethyl, etc.

The polycyclic compounds of the type illustrated by Formula I above, from which the mero- In practice, the starting compounds illustrated by Formula I canbe obtainedby condensing the aforementioned amino substituted heterocyclic compounds with ethyl malonate' according to the procedure of Masters & Bogert, Journal of American Chemical Society, vol. 64 (1942) page 2709 or by the method described in berichte v01. 57 (1924) page 1170.

More particularly, the process involved in preparing the intermediates of structure I comprises condensing amino substituted heterocyclic compounds with ethyl malonate in the presence of alcoholic sodium ethylate. As examples of amino substituted heterocyclic compounds which may be so converted into polycyclic compounds having the structure I, there may be mentioned 2- amino thiazoline, 2-amino selenazoline, 2-amino dihydrothiazine, 2-amino-5-methylthiazoline, 2- amino-4phenylthiaz0line, 2-amino hexahydrobenzthiazol-e, 3-pheny1-5-amino pyrazolone and 2-amino pyridine. When these compounds are condensed; with ethyl malonate im the manner: described; they result i'rr compounds whiclr may be represented by the following structural formulas:

From Z-amino thiazoline s N I/ HQ&3N (IJHQ From 2-amino selenazoline Be N\ H, 5-1 i 8H;

From. 2;- amino. dihycfitotliiazine mew c/ c==o Hr g From 2- amino- 5 methylthiazolines mine of (i=0:

From- 2*-aminrr- F-phenylthiamline From;2raminoahexahgdrobenzthiazoleeand:

Em K H:

From a-phenyl fi-aminc pyrazolone From 2-amino pyridine CiHiSR-E HI Oxonol dyes may be prepared by condensing the pyrimidine 0f structureiLwith a heterocyclic compound having an acetanilido methylene group in one of the so-called; reactive positions. As illustrative of the method, the following equation 50 isgivem.

( CIHUN OCH: 0:4 7

The new merocyanine dyes of the structure II in which n is 3 or more, that is,,the dimethine and poiymethine merocyanines' of this formula, may be prepared by condensing: the diketopyrimidine ofstrueture 13 with a fl-anilinos vinyl, p-acetanilidovinyl derivative; of a cyclammonium quaternary salt, or omegaraldehyde, or omega-ketone derivatives, such as acetylmethyiene; derivatives; or fi allryl mercaptovinyl, or 75 fi-alkyl mercapto fi alkyl vinyl" derivatives theresesame -of, in the so-called reactive position. The procedure involving the use of omega-ketone and B-alkyl or arylmercapto-fi-alkyl or aryl vinyl derivatives results in dyes having an alkyl or aryl tives maybe characterized by the following where aryl is of the benzene or naphthalene series, and Z has .the hereinbefore mentioned significance.

These derivatives, which are claimed in my application Serial No. 633,538 filed on December '7, 1945, now Patent 2,423,218 July 1, 1947, may be readily formed by reacting equimolecular amounts of a compound of structure I and a diaryl formarnidine, such as for example, diphenylformamidine, or arylamino acrolein anils, e. g., B-anilinoacrolein anil hydrochloride; or arylamino-A2.4-pentadienal anils, e. g., glutaconic aldehyde dianilide hydrochloride, in the presence of acetic anhydride. For instance, if this reaction is carried out on the 2,3,6,7-tetrahydro- 5,7-dioxo--thiazole pyrimidine, a compound having the following structural results:

o o=o $=CHNCBHI OCH:

These acetanilidomethylene intermediates may be readily condensed with a cyclammonium quaternary salt having a methyl group in the reactive position in the manner indicated above to form the new merocyanine dyes.

In general, the process of preparing the dyes is advantageously carriedout in the presence of suitable condensing agents. Where acids are given off during the reaction, it is preferable to use a basic condensing agent. Where water is formed during the reactions, it is preferable to use v'vater-binding agents such as organic acid anhydrides, as for example, acetic, propionic and butyric acid anhydrides. It is preferred to use strong organic bases, examples of which are triethylamine, tributylamine, triethanolamine, N- methylpiperidine. Other basic condensing agents may be utiliz'ed'as for example, pyridine, sodium or potassium acetate, sodium ethylate and sodium propionate.

The reactions be advantageously carried out in the presence of a diluent. Lower aliphatic alcohols are preferable for this purpose. Examples of such alcohols are ethyl, n-propyl and isopropyl alcohols. l yridine may also serve as a diluent.

Heatfacilitates the formation of my new dyes. Refluxing the reaction mixture is a convenient .way of forming the dyes. The intermediates "whichare condensed to form my new dyes are to form my new dyes may also :6 ordinarily employed equimolecular amounts although a slight excess of one or the other may be utilized. The basic condensing agent or waterbindmg agent is utilized in suflicient amount to bind the acid or water eleminated from the condensing compounds. While less maybe utilized, it is preferred to use the condensing agent in excess.

The following examples will serve to illustrate but are not intended to limit the invention:

7' V Example 1 1.7 grams of 2,3-dihydro-5H-thiazolo[3,2-alpyrimidine-5,7(6)-dione prepared from 2-amino thiazoline and ethyl malonate in the presence of alcoholic sodium ethylate, and 3.4 grams of 2-(13- acetanilido vinyl) fi-methyl benzthiazole ethiodide were mixed in 30.0 cc. of isopropyl alcohol and 0.5 cc. of triethylamine added and the whole refluxed for 1 hour. The dye precipitates during the course of refluxing. The dye was filtered of! after the reaction solution was brought to room temperature, washed with water, and the dyerecrystallized from alcohol. The dye sensitized'to 570 mu with a maximum at 530 mu.

1.7 grams of 2,3-dihydro-5H-thiazolo[3,2-a]- pyrimidine-5,7(6) -dione, made from 2-amino thiazoline and ethyl malonate, and 3.3 grams of 2 (p-acetanilido vinyl) benzthiazole ethiodide were suspended in 30.0 cc. of isopropyl alcohol and 0.5 cc. of triethylamine added. The mixture was refluxed for 1 hour. The dye which precipitated, was filtered after cooling and washed with water. The dye was purified by crystallizing from methyl alcohol. The dye sensitized to 5'70 mu with a maximum at 530 mu.

Example 3 HzC C/ \C=O 0211f e O I v CH: HJIN\ 'oH=o CaHa (I? CgHt 2.3 grams of 2,3-dihydro-3-phenyl-5H-thiazolo- [3,2-a]pyrimidine-5,'7(6) -dione made from 2- amino-l-phenyl thiazoline and ethyl malonate, and 3.1 grams of 2(5-methylmercapto p-ethyl vinyl) -6-m ethoxy benzselenazole ethiodide and 0.5 cc. of triethylamine were refluxed in 30.0 cc. of n-propyl alcohol for 1 hour. The reaction mixture was cooled and the dye which separated was filteredofi and recrystallized from methyl alcohol. The dye'sensitized to 600 mu and had a sensitizing maximum at 560 mu. V

. Example 4-;

as be 1.8 grams of 2,3-dihydro-6H-pyrimido[23-h]- 1,3,4-thiazine-6,8(YT-dioneprepared from 2- amino-dihydrothiazine and ethyl; malonate and 4.7 grams of z -(fi-acetanilido.viny1).-6-methoxy benzsel'enazoie ethiodide, and 6.5 cc.. of triethylamine were refluxed in-30.0*cc: of n-propyi alcohol for 1 hour. The-dye was crystallized from methyl alcohol. The dye sensitized to 6011 mu and had a sensitizing maximum at 560 mu.

212 grams of. (1175 5 10;l:1-hexahydro-4H;py=- rimido L211- lilhenzothiazole 23(3)" dibne: prepared from Z-amino. hexahydi'othiazole, and ethyl malonate were mixed with 313 grams of 2-(18 acetanilido vinyl) benzthiazcle ethiodide and 0.5 cc. of triethylamine and the mixture refluxed in isopropyl alcohol for one hour: The dye, which separatedmuton cooling, was filtered th. and recrystallized fromalcohol; l -he dye sensitized to 575 mu with a maximum at 545 mu.

Example 6 128 grams" of" 23 -dihydro z methyl-iifi thi azolo[3-,2-al pyrimidine figww -dione prepared from- 2--a-mino 5 -methyl thiazolihe andethyl malonate was mixedwith an! equimeleeular amount of Z-(B-acetanilidm vinyl) benzoxazole ethiodide and 0.5 cc. triethylamine and refluxed in isopropyl alcohol". The dye was recrystallized from ethyl alcohol. It sensitized tn 560 mu with a maximum at 525 mu.

1.8.: grams;' of: ZE-dihydrQ-GEL-pyriinido[23-h]. 1,3,. et-thiazine-6.,B,(7).-dione,. preparedi from. 2- amino dihyd'rothiazihe. and. ethyll malonate; and 2.7; grams ofZ-thibJ-ethyl B acetaniliiiomethyI- .ene dihydrothiazolidoner;wereimixediwith 015 cc. oftri'ethylamihe in 30.0 cc. oi: pyridine. and: refiuxed for 1 hour. The cooled reaction mixture 8 was'd'iluted' with water and'carefiilly-precipitated with perchloric.v acid; The dye=was-frltered oft, dissolved in 3 N'caustic and again carefully precipitated'with perchlorlcacid'. Thedyesensitized to 530,mu with a maximum at 525mm:

Example; 8;

V 1.7, grams, of 2,3 dihydros5Hethiazolbf3g2ral pyrimidine-5,7(6i-dione and an equimolecul'ar amount. of. ethiodide ofv Z-phenylthiobenzthiazol'e were refluxed in 30 cc. of isopropyl' alcohol.v and 0.5 cc. of triethylamine for about 1 hour. A dye having the following formula. was obtained:

1.7- grams of 2,3-dihydro-5H -thiazolo'l33i2m] pyrimidine-5,7(*GJ-dioneandanequi molecuiar amount of- 2-(4-acetanilidobutadienyl? henzothiazcleethiodide were refluxed inthe presence of 0:5 cc. of triethylami'ne' an'd' BO cc. of ethyl alcohol; A dye having-the fol-lowing formula-was obtained? Example. 1 0

One-tenth mole. oila compound; which is produced byreacting equimolecular amounts of 2,3- dihydro-5H-thiazolo[3,2+u.] pyrimidine-5,7 (6) -dione and diphenyl formamidine in the presence of aceticranhydride andhaving; the formula:

Bic-I l" on a silver chloride gelatin emulsion containing a small" amount of silver. bromide and having a total content of 4-5% of silver halide, in which there hasbeen incorporated in 1 kilogramaof'the' emursion' an ethyl alcohol: solution of 20'. milligrams of' the dye.

The dyes may also be utilized to produce, light filters andirrthedyeing of textile'materials';

9 I claim: 1. A cyanine dye of the class consisting of dyes having the following formulae:

wherein X and Z represent the atoms necessary to complete a nitrogenous heterocyclic nucleus usual in the cyanine dye art, n represents a positive integer ranging from 1 to 3, and R represents an alkyl radical.

2. A cyanine dye having the following formula:

wherein Z represents the non-metallic atoms necessary to complete a thiazole nucleus, X represents the atoms necessary to complete a nitrogenous heterocycl-ic nucleus usual in the cyanine dye art, n represents a positive integer ranging from 1 to 3, and R represents an alkyl radical.

3. A cyanine dye having the following formula:

s N /s 0=0n0n=0 t Cifis 4. A cyanine dye having the following formula:

pyridimine compound having the following structural formula:

,c 0='o 2 l wherein Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus usual in the cyanine dye art, and D stands for a member selected from the group consisting of H2 and =CHN-aryl- OCH:

6. A method of forming a cyanine dye having the following formula: V

which comprises condensing in the presence of a basic condensing agent, 2,3-dihydro-5H-thiazolo- [3,2-a]pyrimidine-5-7(6) -dione with Z-(B-acetanilido vinyl) benzthiazole ethiodide.

7. A method of forming a cyanine dye having the following formula:

which comprises condensing in the presence of a basic condensing agent 6,7,8,9,10,11-hexahydro- 4-H pyrimido[2,1 blbenzothiazole 2,4 (3)- dione with Z-(p-aeetanilido vinyl) benzthiazole ethiodide.

ALFRED W. ANISH.

No references cited. 

